We can only hope that one day soon there'll be no reason to single out women as a specific category when we look at up-and-comers in the world of business. But the current reality is this: While the number of U.S. companies owned by women is increasing faster than those of other groups, those companies are responsible for just 6 percent of the country's employees and 4 percent of revenue, according to a 2012 report commissioned by American Express Open. Meanwhile, many studies maintain that women have significantly reduced access to capital and encounter less favorable loan rates. And don't get us started on the discrepancies in compensation between men and women performing equal work.

As relevant (and dispiriting) as these financial truths may be, they are at odds with the fact that fundamentally women are a more powerful presence in business than ever, as a work force and as entrepreneurs, technicians and corporate leaders. Here, we've identified innovators from several significant sectors: science, technology, retail and health, not to mention social and business services. We are certain their contributions and influence will have a profound impact going forward.

Sophia Amoruso, Tastemaker

If Sophia Amoruso has her way, the world is about to get a lot more nasty. Last year the 28-year-old founder and CEO of Nasty Gal, an online purveyor of new and vintage fashion for women, rocketed to prominence from seemingly nowhere after scoring a $40 million round of funding from Index Ventures--investors in Skype, Dropbox and Blue Bottle Coffee. For a retailer with scant discounting and zero debt, Nasty Gal has racked up some seriously drool-worthy numbers: international sales of $128 million in 2012, four times higher than the year before; 535,000 Facebook fans; 420,000 Instagram subscribers; 68,000 Twitter followers; and more than 2 million monthly unique visitors to the website in September 2012.

In 2006 Amoruso was in her garage, watching bids roll in for the one-of-a-kind vintage clothing pieces she had put up on her eBay store. Seven years later she's got a view from Nasty Gal's 10,000-square-foot digs in downtown Los Angeles, boasting arched windows, high ceilings and droves of impossibly cool guys and gals. The bob-haired, bright-lipsticked Amoruso herself arrives in a rock 'n' roll black flared miniskirt, blue sneakers and a rainbow-fringed shag jacket.

At the heart of the brand's success is Amoruso's drive to satisfy the "crazy, freakishly loyal" community that clamors for Nasty Gal's ultra-affordable, young-skewing new merchandise, which is curated from an array of up-and-coming designers, as well as vintage items from luxury brands. "I will never stop making things and imagining cool and trippy things for those girls, and that will become a bigger part of what we do," she says.

Right now Amoruso is on the hunt for more office space in the neighborhood to house her ever-expanding staff--150 employees and counting, with 65 hires in 2012 alone--including executive talent poached from Stella & Dot, Shopzilla, Amazon, Jawbone and Gap. That's in addition to a 500,000-square-foot warehouse that opened in the fall in Louisville, Ky.; the launch of a mobile site; and the simultaneous debut of the biennial Super Nasty print magazine and the brand's first in-house collection, Weird Science, featuring color palettes inspired by computer cables and prints based on data-corruption visuals.

All this, Amoruso asserts, is just the beginning. "We are transitioning from a retailer to a full-fledged brand," she says. "Part of the reason I got to where I am is I never set a goal or look at the top. I like figuring out how to do things myself, and I like the idea of creating an online brand that will last a long time."

Linda Rottenberg, Entrepreneurship Advocate

Linda Rottenberg, Entrepreneurship Advocate

When Linda Rottenberg graduated from Yale Law School in 1993, she knew one thing: She didn't want to practice law. So off to Argentina she went--to work for Ashoka, an organization that supports social entrepreneurs. Tech entrepreneurship was booming in the U.S. But in Argentina? Rottenberg learned that there wasn't even a word for entrepreneur there. "Everybody I was meeting who had big talent aspired to a government job," she says.

There was no venture capital. No role models. No support. That sparked the idea for Endeavor, the New York-based organization Rottenberg launched in 1997 with Peter Kellner, an investor who had witnessed the same lack of advocacy for entrepreneurs during a Harvard Business School trip to China. Endeavor finds what Rottenberg calls "high-impact" entrepreneurs around the world and supports them through intense mentoring--each participant gets his or her own board of advisors--and access to a network of local investors. Rottenberg, who serves as CEO, defines high-impact entrepreneurs as those with "the greatest ability to create jobs, generate revenues and become role models for the next generation."

The basic idea hasn't strayed much from Rottenberg's initial plan. "We had sketched out search, select, support, give back--that the entrepreneurs would start giving back to Endeavor," she says. "On the big-picture level, it is almost exactly what we had envisioned."

But the program's influence is even greater than Rottenberg could have imagined. Since its founding, Endeavor--which has 17 offices around the world and is aiming for 25 by 2015--has worked with 726 entrepreneurs. In 2011 program participants earned $5 billion in revenue and created 200,000 jobs. And they are starting to step up to the give-back portion of the program as well: In 2012 two Endeavor entrepreneurs each gave $1 million to their local offices. "They're now mentors and angel investors themselves," Rottenberg says.

That reciprocation is at the heart of Rottenberg's mission. "The No. 1 factor for catalyzing the [entrepreneurial] ecosystem is successful entrepreneurs investing and mentoring the next generation," she says. "[It's] even more important than institutional venture capitalists."

Olga Koper, Nanotechnologist

Olga Koper, Nanotechnologist

Nanotechnology is all about small--manufacturing with atoms and manipulating materials no bigger than a billionth of a meter--but its potential is Brobdingnagian. Steve Jurvetson of powerhouse venture capital firm Draper Fisher Jurvetson has called nanotech "the next great technology wave, the next phase of Moore's Law and the nexus of scientific innovation that revolutionizes most industries and indirectly affects the fabric of society."

At the crest of this wave is Olga Koper, research leader at Columbus, Ohio's nonprofit Battelle Memorial Institute since May 2011 and holder of more than 30 U.S. and international patents for composition and applications of nanomaterials.

Koper, who describes her research as a "humongous playground to apply science to change and improve lives," isn't your usual ivory-tower type. "A lot of academia and national labs are great at fundamental science but don't know how to turn it into a product," she says. "In business, you have to take calculated risks, have failures and learn from them, and you have to address actual needs of the market--not with a 'nice to have,' but a 'have to have.'"

Back in 2007 Koper joined the charter class of Pipeline, an invitation-only mentoring organization affiliated with the Kauffman Foundation and Microsoft, known for honing business-development skills in new entrepreneurs. As CTO and vice president of NanoScale Corporation, a spinoff of Kansas State University (where she earned her Ph.D. in chemistry), she led the development of commercial products. Among them were FAST-ACT, a nanopowder that absorbs and mitigates toxic and waste chemicals, and an in vitro cancer-diagnosis system--currently in animal and preliminary human testing--in which nanoparticles measure the activity of cancer-specific enzymes in blood and urine using luminescence.

At Battelle, Koper is studying the use of nanomaterials in membranes for water desalination and treatment; supercapacitors (energy-storage devices that provide higher power densities than batteries); and bio-based (rather than petroleum-based) additives used for hydraulic fracturing, or fracking, to retrieve natural gas.

"It's exciting, because the research can make a huge impact in energy storage and the oil and gas industry," she says. "Hopefully we'll see products containing these nanomaterials in the market."

And not a (nano)second too soon.

Yael Cohen, Philanthropist

Yael Cohen, Philanthropist

Yael Cohen has a potty mouth, and she's not afraid to use it. After her mother was diagnosed with breast cancer in 2009, Cohen made her a "F*** cancer" T-shirt, then started a Facebook group by the same name. Before long, the group had more than 1,000 members sharing support. Four years later, and with nearly 66,000 Facebook followers, F*** Cancer has turned into a fast-growing nonprofit.

The primary goal of the Vancouver, British Columbia-based organization is to spread the word about early detection. F*** Cancer has dozens of brand ambassadors using social media to encourage teens and twentysomethings to talk to their parents about getting mammograms, colonoscopies and other diagnostic screenings to "actively look for cancer, not just find it. Cancer is most curable at stage I," Cohen says.

But this isn't your typical charity for the politically correct set. The organization's cheeky attitude and Cohen's seemingly boundless energy have attracted celebrities like One Tree Hill star Sophia Bush to help get the word out. The marketing is edgy: October's "Touch Yourself" campaign in partnership with Women's Health and Men's Health magazines ditches traditional pink National Breast Cancer Awareness Month branding in favor of a naked woman holding her breasts, encouraging women to do self-exams for early detection.

F*** Cancer's December 2012 fundraising brought in roughly $500,000. Cohen has built trust among donors by posting an infographic on the organization's website that tracks incoming donations and expenses. She says that kind of transparency is important to her community, which expects access to information about the organization's activities and how its money is being spent.

"For our parents and grandparents [cancer is] the 'C-word,'" she says. "We want to shift away from that fear-based marketing and focus on the fact that approximately 90 percent of cancers are curable if caught in stage I."

Maria Flynn, Biotechnology Executive

Maria Flynn, Biotechnology Executive

When you're waiting for that pill to kick in to ease your migraine, dragging your kid kicking and screaming to the doctor for a booster shot or holding your nose to down a fish-oil capsule, Maria Flynn feels your pain. That's why she's in the business of making those experiences a bit more tolerable.

Flynn is president and CEO of Orbis Biosciences, a Kansas City, Kan.-based startup that develops original controlled-release delivery systems for the pharmaceutical and consumer product industries. Traditional techniques for making controlled-release solutions (for things like medications, vitamins, flavoring agents and pest-control products) create non-uniform particles that can lead to variable delivery; Orbis' technology creates microspheres of an exact uniform size, allowing for highly precise release rates and dosage control.

The technology is being applied in numerous ways, such as developing a vaccination that includes the follow-up dose; taste-masking oral pills to neutralize flavor; and even working with antimicrobials for the U.S. Department of Defense to improve ready-to-eat meals for the Army.

"It's a challenge to get from the academic lab into a full-scale manufacturing process, so we'd like to be that facilitator of technology in the control-release space," Flynn says. Eventually, she adds, "we'd like to see a turnkey system that can go into a lot of different places."

Flynn, who has an MBA and degrees in civil and environmental engineering, formerly worked in business development for international healthcare IT firm Cerner. Wishing to pursue an entrepreneurial venture, in 2008 she joined with co-founders Bo Fishback and Cory Berkland at Orbis. Her diverse background gave her the ability "to go into industries and learn quickly and put pieces together," she says.

"There's a need for innovative working models, and I think an entrepreneurial setting is a great place to set that up," adds Flynn, who for the past four years has also been involved in Pipeline, a community for Midwestern entrepreneurs in technology and life sciences. "Work with the best people you can, the best partners you can find, and stretch each other farther than you think you might be able to go."

Tara Hunt, Social Marketing Authority

Tara Hunt, Social Marketing Authority

Before Timeline and tweets, before a blog was called a blog, before anyone even knew what a web browser was, Tara Hunt was there. Often labeled a pioneer of online and social marketing, the 39-year-old Canadian has been an observer of the realm's development and a force in influencing it.

Hunt says her own evolution has been "a combination of being enamored and obsessed with the social web and being in the right place at the right time." She was able to experiment in online marketing early on at startups in Toronto and San Francisco, when numbers of followers and likes weren't crucial to anyone's bottom line. There, Hunt found that organic engagement--developing relationships with a community in a natural, hands-on way, rather than pushing a message or brand image--was the most powerful driver of customer loyalty. (She even wrote a bestselling book on the subject: 2009's The Whuffie Factor: Using the Power of Social Networks to Build Your Business.)

Now, says Hunt, who currently works as digital and content director at Tuxedo Agency in Montreal, the rules have changed. Companies want customers immediately, and they want to bypass the work it takes to get them. "Brands [are] vying for attention and throwing a lot of money trying to get that attention and bending the rules of the social sphere," she says. "Social networks like Facebook, Tumblr and YouTube have built a lot of tools to help brands jump the line by paying a certain amount of money." Those tools help support the ecosystem, so they aren't necessarily bad, Hunt says, unless they prevent companies from learning how to truly engage with their customers.

"When it comes to social, small is the new big," she declares. Businesses that take the grassroots tack, "playing by the rules of engagement for building real relationships, not paid-for relationships," are the ones with staying power. Hunt cites Zappos, the darling of social marketing, whose focus on little gestures results in dedicated and satisfied customers who are happy to spread the word.

Hunt likens her industry to a pimply teenager: still making mistakes, still experiencing growing pains. Even her own recent startup, Buyosphere, has evolved, pivoting from a social retail platform offering insight into community buying patterns to a fashion-advice network. And as social marketing continues to find its footing, Hunt is happy to help guide it through adolescence.

Jane McGonigal, Game Developer

Jane McGonigal, Game Developer

It's not every day that a knock in the head leads to an entirely new approach to treating disease, but that's what sparked SuperBetter, Jane McGonigal's free online game, which introduced a radical new approach to the prevention and treatment of depression, anxiety and other neurological conditions.

In 2009 McGonigal banged her head against a cabinet in her San Francisco home, sustaining a concussion that took nearly a year to heal. This led her to use her Ph.D. in performance studies from the University of California, Berkeley, and her experience building collaborative online games for the World Bank and the American Heart Association to develop a game that would allow her to play her way to better mental health. The result was SuperBetter, which launched at the 2012 SXSW Interactive festival. It asks players to set up progressive, daily goals for themselves and enlist friends
or family to keep them on track.

"Games promote positive health aspects, optimism, social support and resilience," McGonigal says. "We know games have the power to change the state of the brain, stimulating parts of the brain that therapy doesn't."

Leaders in science are taking her work seriously. Last year The Ohio State University Wexner Medical Center began clinical trials on the efficacy of SuperBetter to treat traumatic brain injuries, and the University of Pennsylvania Positive Psychology Center greenlighted a randomized controlled user study of the game to treat depression. Results from the UPenn study are expected this spring.

According to McGonigal, the appeal of SuperBetter (which is played by 125,000 people worldwide) is that unlike many medications that treat such conditions, it has no side effects--and people always want to see what works better than current protocols. It's a big promise, and to shepherd her game into the healthcare arena, McGonigal has taken an "entrepreneurial sabbatical" of undetermined length from her role as director of games research and development at Palo Alto, Calif.'s Institute for the Future.

"Ninety-nine percent of teenage boys and 94 percent of teenage girls in this country play online games," she says, equating the acceptance of gaming by the next generation to TV watching. She also points out that there are more than 1 billion people playing online games around the world. "And all these people are learning from their failures," she says. "Gamers fail 80 percent of the time, but they keep playing. There's a connection between becoming a good gamer, learning from failure and being better at making life a game."